The invention relates to devices for the insertion of catheter guidewires into blood vessels. A guidewire is inserted so that a catheter, which is coaxially engaged with the guidewire, may be inserted into the. blood vessel. The guidewire is then withdrawn, and the catheter is ready for further positioning and use. It is imperative that guidewires be inserted without contamination of the sterile field to avoid unnecessary infection of the patient.
Guidewires are generally comprised of a coiled spring guide with a distal tip and one or more wires running longitudinally within the spring. Such guidewire constructions are disclosed in U.S. Pat. Nos. 4,003,369 and 4,676,249. Catheters are generally hollow, flexible tubes used to convey liquids or other instruments to a desired location in the body.
Existing systems for guidewire insertion suffer from continued problems arising from the lack of ease in manipulation and the exposure during insertion to a non-sterile environment. Normally, a guidewire is removed completely from its package prior to use, is wound in the physician""s hand and inserted through a needle extending into the patient""s artery, or through a cannula into some other body cavity. Three or more hands are required to hold the needle stationary while the xe2x80x9cJxe2x80x9d guidewire is pulled through a straightener, then pushed through the port in the needle. The inadvertent extension of the guidewire prior to insertion and the awkwardness of manipulation during insertion leads to contamination of the sterile field and the patient""s blood stream. It is also desirable that the physician or operator be able to tactilely sense the progress of the guidewire tip during insertion to insure better control.
A catheter guidewire is packaged for use in a hollow tube or casing which maintains a sterile environment for the guidewire prior to use. The guidewire is displaceable through an outlet at one or both ends of the tube for insertion into the desired artery or body cavity.
An aperture in the casing is located adjacent to the outlet so as to provide access to the guidewire surface. By applying a lateral frictional force to the surface of the guidewire in the direction of the outlet, the guidewire can be displaced through the narrow tube and the outlet.
A second tube attached to the outlet and disposed to receive the guidewire as it exits the casing can be used to straighten a xe2x80x9cJxe2x80x9d guidewire prior to entering a canal through a needle or cannula. In a preferred embodiment of the invention, the aperture for frictionally displacing the guidewire can be located in the straightening tube. The invention thus provides a means for maintaining a sterile environment during storage and insertion of the guidewire. Only one hand is necessary to operate the dispensing mechanism while the desired sensitivity to guidewire placement in maintained.
In another preferred embodiment, a moveable member is positioned over the aperture to maintain a sterile environment for the guidewire while at the same time providing the frictional force to displace the guidewire. This moveable member can be hand actuated rollers or a slidable bar or any other suitable mechanical device that maintains the tactile sense of the operator with regard to directing the guidewire through the system. The member which can be manually depressed to frictionally engage the guidewire surface. The moveable member can also be placed in a housing used to hold the two ends of the casing.
One embodiment of the system provides for the transmission of an electrocardiographic signal through the guidewire to determine the position of the distal end of the guidewire that has been inserted into a body canal. The housing that holds the frictionally engaging member referenced above is positioned about the aperture and used to transmit an internally generated electrical signal onto the conductive guidewire element.
The above, and other features of the invention, including various novel details of construction and combination of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular guidewire advancement system embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principle features of this invention may be employed in varied embodiments without departing from the scope of the invention. For example, the device can be utilized in the catheterization of any body cavity or artery, or alternatively in any veterinary applications involving catheterization procedures.